Occasional Papers of the Museum of Zoology 9 



of the Lake Michigan beach drift as observed on the Ilhnois 

 shore, together with a discussion of the factors which con- 

 tribute to the phenomenon. Other contributions, deahng prin- 

 cipally with the drift on the ocean beaches, have been made by 

 Bueno^ and by Parshley.*^ 



My camp on the Sawyer Dunes was very favorably situated 

 for observations on the beach drift, and I watched the beach 

 daily during the three weeks of my stay there. Although a 

 considerable number of insects were washed ashore at various 

 times, I was not so fortunate as to witness any such remark- 

 able drifts as have been reported by Needham. 



The most extensive beach drift which occurred during the 

 early summer in 1920 took place before my field work was 

 begun, probably some time about June 20, and even on July 4, 

 when I first visited the dune region, the remains were very 

 evident. The insects were not piled up in masses, but merely 

 formed uneven lines along the beach, from two to four inches 

 wide, mixed with cinders and other flotsam from the lake 

 steamers. Rhynchophora, Scarabaeidae, and Carabidae were 

 predominant : in fact, none but hard-bodied forms had per- 

 sisted until this date. Of the Hemiptera, Podisus maculivev- 

 tris was easily the most abundant species, though other Penta- 

 tomidae were also common, and some forms belonging to other 

 families were found. 



During the first half of July insects were found on the 

 beach in fair numbers, but later in the month the drift became 

 negligible. Coleoptera continued to hold first place, with the 

 Rhynchophora, Scarabaeidae, and the larger Carabidae esoe- 



^Hemiptera in Beach Drift. Etit. News, 26: 274-279, 1915. 

 Remarks on Heteroptera in Beach Drift. Bull. Brookl. Ent. Soc, 

 15: 142-14S, 1920. 



*■' Insects in Beach Drift. I — Hemiptera Heteroptera. Can. Ent., 

 49: 45-48, 1917. 



